The present invention relates to a baby trailer and more specifically, to a frame structure of baby trailer, which facilitates setting the bottom frame between an extended position and a received position.
U.S. Pat. Nos. 8,444,173 and 7,341,265 disclose a baby trailer that allows adjustment of the front bar and rear bar of the bottom frame between an extended position and a received position. However, when collapsing the front bar and the rear bar, the user needs to unfasten the fastening member at the front bar and the fastening member at the rear bar. On the contrary, when extending out the bottom frame, the user needs to extend out the front bar and the rear bar, and then to fasten up the fastening member at the front bar and the fastening member at the rear bar. This operation procedure is inconvenient, wasting much labor and time.
The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a frame structure of baby trailer, which can be conveniently and rapidly collapsed through a unilateral operation to reduce the dimension, facilitating package, delivery and storage.
To achieve these and other objects of the present invention, a frame structure of baby trailer comprises a bottom frame that comprises a front frame bar, a rear frame bar and opposing left and right frame bars respectively pivotally connected between the front and rear frame bars, two -shaped upright support frame bars respectively connected with respective front and rear ends thereof to the bottom frame, and a top transverse frame bar connected between the two upright support frame bars at a top side. The front or rear frame bar of the bottom frame is retractable, and can be set between an extended position and a received position and then locked in the extended position by fastening means.